Improvement in spirit-levels



A. P. O'DHOLM.

. Spirit Lever.

Patented 666. 26, 1669.

Fig.

N. PETERS. F'NOYO-LITHOGRAPNEnA WASHINGTON, D C.

tlnted (55mm stent dimite.

A. I). ODHCLM, CF BRIDG-EPORT. CONNECTICUT.

Letters .Patent N o. 96,140, dated October 26, 1869; antedated October 16, 1869.

IMPROVEMENT IN SPIRIT-LEVELS.

The Schedule referred te in these Letters Patent and making part of the same To ll whom it may concern Be it known that I, A. 1. ODHOLM, of Bridgeport, in the county of Fairfield, and State of Connecticut, have invented a new and improved Plumb and Level land I do hereby declare that the following is a full, clear, and exact description thereof, which will enable other's skilled in the art to make and use the same, reference being had to the accompanying drawings, forming part of' this specification, in which- Figure 1 is a front view of my invention.

Figure 2 is a section of the same, taken in the line :c x ot' fig. 1.

Similar letters of reference indicate like parts.

This invention relates to a new and improved plumb and level, ot" that class in which the liquid is confined ivithin acircular chamber.

The invention consists in a novel manner of` constructing the implement, whereby the eval'ioratiou of the liquid is effectually prevented, which renders it far more desirable and durable than implements ot this class which have hitherto been made.

In the accompanying sheetof drawings- A represents the stock of the implement, which is of rectangular form, the long sides a c being parallel with each other, and the short sides or ends b b par- ,allel with each other, and ay a at right angles with b b,

as shown in fig. 1.

In this stock, which may be made of wood, there is bored, at one side, a circular hole, which extends about one-third of its thickness; and this hole receives a circular box, B, half filled with suitable liquid.

The rim C of this box is made of vulcanized rubber. After the rim is turned, it is softened by heat, and driven upon a slightly-tapered mandrel, and thereby expanded to a certain degree.

When the rim is cool, a hole is drilled through, in the outer edge, and the rim is then fitted in a proper chuck, and turned at its inner side, so as to leave a shoulder, d, and two circular pieces of glass, e c, are then fitted within the rim.

These pieces of glass are ground perfectly true, and .are fitted snugly within the rim, and against the shoulder d, (see fig. 2,) causing a space to be left between the glasses, which forms the liquid-chamber ax.

The rim C is then-heated, which causes it to contract, so that the edges of the pieces of glass e e will become embedded in the rim, and perfectly air-tight joints obtained, without using any cement, which has been hitherto used.

The chamber being finished, acircular graduated dial or index g is placed on the back glass, (that goes first into the stock,) which is visible through both glasses; or an enamelled dial can be substituted for the back glass and dial aforesaid. Then the liquid is poured into the chamber, through the hole in the rim, and is filled to the centre of the dial, and the hole in thevrim is then plugged up. ',lhe box, being finished, is then inserted in the stock.

The box B, constructed of vulcanized rubber, or other equally suitable material, in the manner described, will always be air-tight, so that the liquid cannot escape by evaporation.

Hitherto, these boxes have been constructed of' metal, and the expansion and contraction ofthe latter render it impossible to have an air-tight joint between the edges of the glass andthe inner side of the rim. The consequence is, that the liquid in the chamber gradually evaporates, and the implement is soon rendered useless. This contingency is fully obviated by my invention. l

The graduated dial g is an important feature ot' my invention, as the liquid is directly in front of' it, and the horizontal surface, or any degree of inclination therefrom, of the liquid is rendered distinctly visible.

Having thus described my invention,

I claim as new, and desire to secure by Letters Patent- As a new article of manufacture, the spirit-level and plumb, constructed, as described, of' the hard-rubber box B, (which contains the alcohol,) shrunk upon the glass plates e e, one of which is provided with the 'disk g, in the manner described, for the purpose specified.

A. I. ODHOLM.

Witnesses:

JEssE S. NASE, L. M. SLADE. 

